ATLAS e-News

News from the pit

11 December 2007

A small wheel undergoing safety tests in Building 191

ATLAS, the world’s largest three-dimensional jigsaw, is gearing up to receive its final two pieces – the small wheels are almost ready to be moved to the pit.

“Once the small wheels are installed, we can say that ATLAS is finished from a detector point of view,” says Ariella Cattai, leader of the small wheel team. “This is a milestone of honour.”

Probably because of their size, the small wheels have always been a bit in the shadow of the Big wheels. Their construction only began 12 months ago. Ariella says construction has proceeded so rapidly because the young physicists and engineers that dominate the small wheel team are highly motivated and enthusiastic. “The young people have been heavily involved and that makes me proud,” she says.

Construction has finished on one of the small wheels, and the other is undergoing final tests. The small wheel team is taking full advantage of the slight delay in the pit caused by the recent end cap magnet incident to do some additional alignment studies before installation.

“Moving the wheels will be a real challenge,” says Ariella. “We don’t just roll them! They need to be ‘packed’ in a frame for transportation.” The weights involved are enormous – each wheel weighs 100 tons. Last week in Building 191 the small wheel team conducted safety tests to show that the frames are strong enough for the job. “This safety test is one of the biggest ever done at CERN in terms of size and weight,” Ariella says.

Those tests should soon be completed and the wheels will be moved to the detector cavern early in January. “When they do arrive we will have a big party to celebrate, believe me!” says Ariella. The new year will be an important one for ATLAS, and it is set to start on a positive note. Colin Barras